When searching for related blogs to comment on, I usually use the following search term in Google:
"[Keyword]" "Post A Comment" INURL:blog name email website
This returns results relating to my keyword, that contain the text "post a comment" and have the word "blog" in the URL, and also contain the words "name", "email", and "website" (often at the comment submission form).
But, this is what I figured out after a jump to number one:
I had hundreds of backlinks coming from one domain, I looked into it a little more and found that this domain had a "recent comments" widget attached the sidebar which put my link in front of hundreds of pages and probably THOUSANDS of viewers.
This influx of backlinks jumped me up to #1 in Google and I stayed there even after my comment was pushed off the recent comments widget.
Now, whenever making blog comments, I remember to add the tag "Recent Comments" to my search tag to find these goldmines:
"Recent Comments" "[Keyword]" "Post A Comment" INURL:blog name email website
This definitely won't be a new trick to some of you but I encourage some of the newbies and blog commenters to try this little tip.
You will need to wait for the moderator to approve the comment in most cases so remember to comment on a blog where the recent comments where written within the last few months.. Otherwise you may have hit an abandoned blog.
Hope you guys get some use out of that!